PS0203

Verify program contains G97 (constant speed mode) before G84/G74 rigid tap cycle. Check that G96 (CSS mode) is not active. Review program block prior to alarm occurrence.

Check parameter 4000#0 (NOC) - must be set to 0 for rigid tapping (spindle position coder required). Navigate SYSTEM > PARAM > search 4000, verify bit 0 = 0.

Verify parameter 4002#1 (RTP) is set to 1 to enable rigid tapping mode. This parameter activates the rigid tap function for synchronized spindle-axis motion.

Check DIAGNOSIS > SPINDLE screen (exact path varies by series: 0i/16i = DIAG #400-409, 30i/31i = DIAG #7000-7099). Verify spindle mode display shows normal speed control, not CSS or other special mode.

Check DIAGNOSIS > SPINDLE screen for position feedback signal. On 0i/16i check DIAG #408 (spindle serial data reception), on 30i/31i/32i check DIAG #7028 (SP serial communication status). Value should indicate active serial communication.

Verify spindle amplifier LED shows normal operation (steady green on αi/βi series). Flashing or red LED indicates encoder or communication fault. Check SP cable connections at both amplifier and motor encoder.

Confirm parameter 4020 (spindle gear ratio) and parameter 4021 (position coder pulses per revolution) match actual hardware configuration. Incorrect values prevent proper position tracking during rigid tap.

Execute spindle orientation command (M19) separately to test position feedback loop. If M19 fails or times out, position coder system is faulty. Check diagnostic #7028 during M19 execution for encoder data validity.

Do not perform M19 test with tool in work - use safe Z position

Check DIAGNOSIS > SPINDLE for actual spindle speed vs commanded speed. On 0i/16i check DIAG #400 (commanded) vs #401 (actual). On 30i/31i/32i check DIAG #7001 (commanded) vs #7002 (actual). Verify speeds match within tolerance.

Review parameter 4710 (spindle speed arrival detection level in rpm) and parameter 4711 (arrival detection time in msec). Typical values: 4710=50rpm, 4711=500msec. Widen detection window if spindle speed is marginally stable.

Verify parameter 4716 (spindle speed command clamp minimum) is not set too high for the programmed tap speed. If tap speed is below this parameter value, spindle cannot command proper speed for rigid tap cycle.

Check DIAGNOSIS #7008 (spindle load meter on 30i/31i series) or DIAG #401 (on 0i/16i). High load values (>80%) may prevent spindle from reaching commanded speed. Inspect mechanical load, bearing condition, or belt tension if load is excessive.